1. Draw the structure of the nucleotide, adenosine trip te (ATP) Tiphosphate a.
ID: 186109 • Letter: 1
Question
1. Draw the structure of the nucleotide, adenosine trip te (ATP) Tiphosphate a. Indicate the location of each of the following bonds and explain what is linked by each type of bond: the N-glycosidic bond. Tra is a type arboh drare- - between an aspardae side chan amide and a Augar. ihs t phosphoan e bonds. (How many are there?) - phosphomonoester bonds. b. Explain the different properties of these bonds. Does ATP contain any phosphodiester linkages? c. What differs among the structures of ATP, AMP, ADP and dATP? d. Where are the positive and negative charges in this molecule? What is the net charge at pH 7?Explanation / Answer
The phosphomonoester type of bonding in nucleic acid monomers is corroborated both by their chemical properties and by their behavior in the presence of enzymes specifically cleaving phosphomonoester bonds. Enzymes are known, namely, phosphomonoesterases (PME), that break down phosphonucleosides to phosphoric acid and nucleosides. Acid hydrolysis of a phosphonucleoside gives pentose phosphate, but if hydrolysis is conducted under mild conditions at pH 4 (phosphomonoester bonds at this pH value are most labile as a rule), dissociation to a nucleoside and phosphoric acid takes place
The phosphate groups in the phosphodiester bond are negatively charged. Because the phosphate groups have a pKa near 0, they are negatively charged at pH 7. This repulsion forces the phosphates to take opposite sides of the DNA strands and is neutralized by proteins (histones), metal ions such as magnesium, and polyamines.
In order for the phosphodiester bond to be formed and the nucleotides to be joined, the tri-phosphate or di-phosphate forms of the nucleotide building blocks are broken apart to give off energy required to drive the enzyme-catalyzed reaction. When a single phosphate or two phosphates known as pyrophosphates break away and catalyze the reaction, the phosphodiester bond is formed.
Hydrolysis of phosphodiester bonds can be catalyzed by the action of phosphodiesterases which play an important role in repairing DNA sequences.
The phosphodiester linkage between two ribonucleotides can be broken by alkaline hydrolysis, whereas the linkage between two deoxyribonucleotides is more stable under these conditions. The relative ease of RNA hydrolysis is an effect of the presence of the 2' hydroxyl group.
(c)ATP, ADP, and AMP differ in the number of phosphates and the amount of energy obtained by each compound.
ATP stands for adenosine triphosphate. ADP stands for adenosine diphosphate. AMP stands for adenosine monophosphate. Therefore, one difference between ATP, ADP, and AMP is the number of phosphates associated with each compound.
Another differences between the three molecules is the amount of energy stored within each molecule. Simply put, the more phosphates, the more energy stored. Thus, ATP has the most stored energy and AMP has the least amount of stored energy.
ATP is the main energy source for most cellular functions. ATP is created during cellular respiration in the mitochondria of eukaryotic cells. During cellular respiration, the sugar called glucose (C6H12O6) and oxygen gas (O2) is converted into carbon dioxide gas (CO2), water (H2O), and ATP.
The energy within ATP is released in order to perform everyday cellular functions as phosphates are removed.
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